Casing-shoe.



J. A. OLINGEB. & J. H. WALKER.

CASING SHOE.

APPLICATION IVILED 00T.22, 1912.

Patented Mar. 10, 1914 fizz/22222252443343 JamesA O Jameafl WELL/$67 INVENTORSi WITNESSES ATTO R N EY UNITED STATES PATENT OFFICE.

JAIBS 314M801! OLINGBB *1) JAKE HAROLD WALKER, OF WEST- GHICAGO, ILLINOIS.

CASING-SHOE.

' specification of Letters Iatent.

Application filed October 22, 1912. Serial No. 727,195.

Patented Mar. 1o,1914.

To all whom it may concern Be it known that we, JAMES Anmson OLINGER and JAMns HAROLD WALKER, citizens of the United States, residing at West Chicago, in the county of Dupage and State of, Illinois, have invented a new and useful Casing-Shoe, of which the following is a specification.

This invention has reference to improvements in well casing shoes designedto be applied to the end of the casing being driyen into a well boring to cut away any pro ections which may be found therein and so rotect the entering end of the casing from injury.

In accordance with the present invention the shoe is provided with an entering end diametrically enlarged to provide clearance for the following casing and the entering end is corrugated or waved so as to provide a circular series of cutters in alternation, these cutters being relatively projected and retracted axially. In this manner a wavy cutting edge is provided having all the advantages of a circular series of teeth, but p'ossessin none of the disadvantages of such series 0 teeth, which latter in practice have been found to readily break. At the same time the strength of a circular cutting edge is retained 'but the shoe of the present invention has the advantage over a circular edge in presenting a continuously changing shear edge in most part engaging the material to be displaced at an angle,

thus greatly facilitating the operation of the tool.

The invention will be best understood from a consideration of the following de tailed description taken in connection with the accompanying drawings forming a part of this specification, with the further understandin that while the drawings show a practica form of the invention it is not limited to any strict conformity with the showing of the drawings, but may be changed and modified so long as such changes and modifications mark no material departure from the salient features of the invention. y

In the drawings :Figure 1 is a longitudinal section of the casing shoe witha portion of the casin or operating member carrying the shoe. ig. 2 is an elevation of the shoe. Fig. 3 is an edge view of the bot tom or working end of the shoe.

Referring to the drawings, there is shown a shoe 1 in the general form of a cylinder with one end 2 of eater external diameter than the main portion of the shoe and joinlng the body 0 the shoe by a taper part 3. The shoe is shown in Fig. 1 as carried by an operating member or casin 4 and the interior diameter of the end 2 o the shoe may be the same as the interior diameter of the casing 4. At a distance from the end 2 the internal diameter of the shoe is expanded forming an annular shoulder 5 adjacent which the interior surface of the shoe is screw threaded, as indicated at 6, and the casin 4 is correspondingly screw-threaded to ta e into the threads 6 and abut against the shoulder 5, so that when the parts are in operation the lower end of the casing 4 is protected by the shoe 5, while the threads 6 or the corresponding threads of the shoe are protected from stripping by the engagement of the lower end of the casing 4 with the shoulder 5. The enlarged end 2 of the shoe has its end surface 7 waved or corrugated circumferentially forming a series of rounded projections 8 and hollows or valleys 9 extending in the same direction as the longitudinal axis of the shoe. The face or end 7, however, is inclined from the outer edge of the large end 2 of the shoe toward the inner edge thereof in an oblique direction toward the other end of the shoe, so that the extreme edge of the enlarged end of the shoe as indicated at 10 constitutes a cutting edge shaped by the wavy or corrugated form of the end of the shoe into rounded or convex teeth joined by reversely rounded or concave valleys or grooves, wherefore the cutting edge is made up of many shearing portions merging gently one into the other without any abrupt shoulders.

The teeth being widely extended circumferentially at the bases are proof against breakage while the cutting edges of these teeth are throughout their lengths in shearing relation to the parts engaged thereby, so that any projections in the well hole which would interfere with the insertion of the Of course, in the case of a cylindrical or concentric cutting edge throughout no teeth at all are present and consequently cannot break, but the advantage of the shear out is lost and this advantage is also lost in the case of axially extended teeth projecting abruptly from the main body of the shoe. The corrugated form of the cutting edge is also advantageous in case of a turning movement being imparted to the casing, in which case not only will the projecting portions not break but the shearing action is still available. Furthermore, the corrugated cutting edge presents a longer cutting edge than is possible with either an abruptly toothed edge or a smooth circumferential edge. The casing shoes have the cutting edges hardened and practice has demonstrated that breakage is frequent where axially extended teeth abruptly shouldered at the sides are employed.

What is claimed is I 1. A casing shoe having the outer edge of its active end of sinuous configurationforming a series of teeth convexly curved at their outer ends and joined at their bases by concavely curved portions.

2. A casing shoe having the outer edge of its active end of sinuous configuration forming a series of teeth convexly curved at their outer ends and joined at their bases by concavely curved portions, the outer and basic curved portions of the teeth being of substantially equal extent and the active end face of the shoe being beveled away from the outer edge.

In testimony that we claim the foregoing as our own, we have hereto affixed our signatures in the presence of two witnesses.

JAMES ALLISON OLINGER. JAMES HAROLD WALKER.

Witnesses:

LOUIS 80111211., A. E. HARPER. 

